Building Animal Modified


Alright guys,
I am looking to order what is needed to build up my Stock Animal (already has a world formula rod, HD duel valve springs, 12k coil, and I’m pretty sure billet flywheel) to be bigger/better than my Ltd. Mod animal I’m currently running. Have been looking at Jimbo’s big valve head kit, but don’t know how much that will improve HP. Not looking to spend over $800 before shipping, but if more (within reason) would yield better results, I’m all ears. Looking for upgrades that don’t require machine work, and was wanting to stay on the 304wx blueprinted Tilly from Dynocams, but realize that may need upgraded and I’m not against doing so.
Upgrades, including kits, heads, cams, and valves, etc... all would be greatly appreciated.
This is just meant to be a mid-end of season upgrade for the stocker, while my grandfather is in town and I don’t need to pay freight and labor fees. Still planning on building an open (hopefully) at the end of the season on my current limited mod but just not sure where to start for this one in the meantime.

Thanks again!
I have a faster motors head like mention above with his roller rockers and thought it was a very nice piece for the money. You will also need a set of good push rods for the extra spring pressure. A 308 cam and you will ready to roll
Personally, I don't think the 304 will keep up with a good flowing big valve head.
It is a good match for a limited modified (ie stock valves and ports.)
I'm thinking Jimbo's head will outflow it, but that would be a better question to ask him personally.

Within your budget, a billet head would be a real nice upgrade, but again, you'll still be needing a bigger carb to handle it.

?Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
Carlson Motorsports on Facebook
30 years of service to the karting industry
Linden, IN


Hate asking for advice and going a different direction after following a recommendation again to Randy at DynoCams. Bought the open head (1-1/4 & 1-1/8” valves) from dyno cams after talking to Randy, 308 billet cam, extreme pushrods, lifters, and a .990” flared tip header, as well as a couple odds and ends. Was told the HL304 tilly would work just fine with these internals. Not opposed to getting a bigger tillotson to fit it’s needs, but which carb would be best (380?) and what would be the symptoms of a carb being too small?
That combo sounds fine. Too small of a carb is like going running and breathing through a straw. If the engine can't breathe, it can't make power.
308 is real conservative on cam for an open - are you using 1.3:1 ratio roller rockers? @ .308" lift, that carb will be plenty. @ .400" lift, that engine will have it's tongue hanging out in my opinion.